Thoroughly mix orange juice concentrate with water, butter and pectin in a large sauce pan.
Bring to a full rolling boil that cannot be stirred down.
Add sugar all at one time.
Bring mixture to a full boiling roll and boil exactly one minute, stirring constantly.
Remove from heat.
Skim off foam.
Ladle hot jelly into prepared jars to 1/4 inch of top.
Top with two-piece lids.
Process 15 minutes in a boiling-water canner.
Makes 6 half-pint jars.